字典的键是唯一的,因此第一个键即为第一个插入的键。 # 创建一个字典my_dict={'a':1,'b':2,'c':3}# 获取第一个键first_key=next(iter(my_dict))# 获取第一个值first_value=my_dict[first_key]print(f'The first element in the dictionary is:{first_key}:{first_value}') 1. 2. 3. 4...
you can see how to get first value in python dictionary. I explained simply about python 3 get first value in dict. We will get first value from python dictionary using next() and iter() functions. So, without further ado, let's see simple examples: You can use these examples with ...
print("First element is greater than 10.") 在这个例子中 ,如果my_list是空的,my_list and my_list[0] > 10的判断会立即停止于my_list(因为空列表在布尔上下文中为False),避免了尝试访问空列表的第一个元素而导致的IndexError。 1.2 条件赋值技巧 利用短路特性 ,可以优雅地实现条件赋值,无需显式使用if-...
.fromkeys(('x','y'),-1):fromkeys()创建一个默认字典,字典中元素具有相同的值3.dict1.keys():获取字典的键值列表4.dict1.has_key('x'):...判断字典中是否有‘x'键值,返回bool型5.dict.get(key,default):返回键值key的值,若是key不存在,返回default的值6.dict.items():返回键值对列表值7.dict....
search_text(source_link, page, text)returnget_links(parsed_source, page)defget_links(parsed_source, page):'''Retrieve the links on the page'''links = []forelementinpage.find_all('a'): link = element.get('href')# Validate is a valid link. See GitHub for details... ...
print dict['a'] ## Simple lookup, returns 'alpha' dict['a'] = 6 ## Put new key/value into dict 'a' in dict ## True ## print dict['z'] ## Throws KeyError if 'z' in dict: print dict['z'] ## Avoid KeyError print dict.get('z') ## None (instead of KeyError) ...
driver.find_element(By.PARTIAL_LINK_TEXT,"上传资料").click() TAG_NAME 例:login.html页面获取form标签name属性"daniu"并输出 1 print(driver.find_element(By.TAG_NAME,"form").get_attribute("name")) CLASS_NAME 例:login.html页面密码框:"passwd" ...
dict.fromkeys(["name","age"],'ikun') {'name': 'ikun', 'age': 'ikun'} get方法 get方法可以获得字典的键的值,如果该字典包含这个键则返回该键的值,如果没有包含这个键则返回None,看下面的例子: a = dict(name = "coco",age=2,number="001") a.get("name") 'coco' print(a.get("momo"...
tuplename = (element1, element2, ..., elementn) 其中,tuplename 表示变量名,element1 ~ elementn 表示元组的元素。注意,当创建的元组中只有一个字符串类型的元素时,该元素后面必须要加一个逗号 , ,否则 Python 解释器会将它视为字符串。 tuple1 = ("Happy") print(tuple1) print(type(tuple1)) tuple...
The sorted() function returns a list of sorted values, so you wrap its call with dict() to build a new sorted dictionary. In the first call, you sort the items by value in ascending order. To do this, you use a lambda function that takes a two-value tuple as an argument and retur...